Rotary axial impact type earth boring tool



Feb. 1, 1966 J. c. HASPERT 3,232,361

ROTARY AXIAL IMPACT TYPE EARTH BORING TOOL Filed March 8, 1965 5 Sheets-Sheet 1 INVENTOR. 56 JOHN 6. #43 527- BY l Feb. 1, 1966 J. c. HASPERT 3,232,361

ROTARY AXIAL IMPACT TYPE EARTH BORING TOOL Filed March a, 1963 5 Sheets-Sheet 2 I NVENTOR. JOHN 6. #451 597 Feb. 1, 1966 J. c. HASPERT 3,232,361

ROTARY AXIAL IMPACT TYPE EARTH BORING TOOL 5 Sheets-Sheet 5 Filed March 8, 1963 T K 62 z /OH/V 6. 1 /45/ 527 INVENTOR 47'rae/vi/ United States Patent 3,232,361 RDTARY AXIAL IMPACT TYPE EARTH BORING T001.

John C. Haspert, Arcadia, Calif., assiguor to dmith Industries International, Inc, a corporation of California Filed Mar. 8, 1963, Ser. No. 263,942 Claims. (Cl. 175-402) This invention relates to the drilling of bore holes in earth formations and the like.

The drilling of wells and other similar formations in the earth is customarily done by one of two conventional methods. One of these is the well known auger drill which receives a rotary drive through a conventional kelly bar and has an auger type bit which is adapted for drilling, and lifts the cuttings. This is a drilling method for materials in the lower strength fields, for example 100 pounds per square inch.

The other common method of drilling such formations is the standard air percussion tool which is driven by air and delivers an impact blow to the attached cutting head. A reciprocating hammer or piston delivers the impact blow. The air passes through the percussor and is discharged through one or more holes in the face of the cutting head. It is conventional practice to have a rotating drive applied through a kelly bar in this type of drilling. The percussion type drilling tool is generally limited to hole diameters ranging below inches.

An auger drill does its job by virtue of carrying a dead weight which exerts a crushing force in a downwardly direction on the material being drilled. Presumably by increasing the amount of this weight the drilling capabilities are increased. But an impact or percussion tool provides the equivalent of such added weight without, however, requiring either the weight itself or the mass or volume associated therewith. A percussion tool could not be associated with a conventional auger drill, because the mechanical construction of the conventional auger drill is such that it would not have any feasible amount of useful life in firmer material when subjected to the impact of the percussion force.

The present invention has been conceived and developed to overcome the limitations of prior art apparatus, and as a result has produced a tool combining the best features of both forms of drilling tools. The advantage of the percussion type is retained, however a new type of bit is required. The advantage of the auger type is also retained through its capacity to remove cuttings from large-diameter holes of the order of 15 inches and larger. The tool of this invention has its maximum usefulness in medium hardness formations.

The tool of the present invention does not eliminate the necessity of periodically taking the tool out of the hole in order to dispose of accumulated cuttings, as is done in conventional auger type drilling. However, it does have a substantial capacity for accumulating cuttings between such periodic removals. This large capacity is provided first by the auger, and second by a hopper at the to of the auger, which is loaded by air discharge from the bit head associated with the auger. The cost of an auger alone which would be long enough to accomplish similar results, would be excessive in comparison with the combination of auger and hopper.

It is therefore the general purpose and objective of this invention to provide an improved drilling tool for making bore holes in earth and similar formations which overcomes the aforementioned and other disadvantages and shortcomings of prior art drilling tools.

A more particular object of the invention is to pro- Federated Feb. l, 1966 vide a novel drilling tool combining the best features of both auger and impact types of drills.

Another object of the invention is to provide a combination auger and impact drill having a novel hopper portion for accumulating a substantial amount of cuttings during each drilling step.

An additional object of the invention is to provide an improved combination auger and impact drill having a novel tooth construction of the drill head.

A further object of the invention is to provide a drill adapted to drill harder material than is presently common to auger drilling.

Another object of the invention is to provide a mechanism which has a reliable rotary drive for the auger type of drill, and at the same time a reliable percussion drive for the percussion type of instrument.

A further object of the invention is to provide an improved drill combining the advantages of rotary and impact types of drilling utilizing an air flow that assists in lifting cuttings from the drilling head to a hopper located at the top of the auger portion of the drill.

With these and other objects and advantages in mind the invention can be more fully understood from the following specification, considered in conjunction with the accompanying drawings. In the drawings:

FIGURE 1 is an elevation view partly in section of a drill embodying the present invention;

FIGURE 2 is a sectional view of the bearing sleeve shown in FIGURE 1;

FIGURE 3 is a sectional view taken along line 33 of FIGURE 1;

FIGURE 4 is a view of the bit head as seen from line 44 of FIGURE 1;

FIGURE 5 is a sectional view taken along line 5-5 of FIGURE 4;

FIGURE 6 is an enlarged axial section through a standard impact generator or percussor embodied in the present drill;

FIGURE 7 is an enlarged section taken on line 7-7 in FIGURE 6;

FIGURE 8 is an enlarged section taken on line 8-8 in FIGURE 6;

FIGURE 9 is a perspective view, partly broken away, of a control rod embodied in the percussor.

Referring more particularly to the drawing the drill of this invention is indicated generally at Ill and comprises a percussor 11, a double-flighted auger 12 having a hollow stem 13 and a bit head 14 secured to the lower end of stem 13. Percussor 11 will be described in detail shortly. Stem 13 of the auger is secured as by a mounting adapter 15 to the impact piston 16 of the percussor l1 and the percussor is secured by a suitable fitting 17 to the lower end of a kelly bar 18. Percussor 11 extends through and has a bearing mounting in a bearing sleeve 20 which is formed with a stabilizing shoe 2?. which engages the wall of the bore hole being drilled, to retain the sleeve against rotation. Percussor II has an air chamber 22, the wall of which is formed with a plurality of apertures 23 which communicate with an external groove 24 in the Wall of the percussor 11 substantially midway of the sleeve 20 which has an air inlet fitting 25 in communication with groove 24. An air hose 26 is connected to fitting 25 and extend upwardly through the well bore hole to an air compressor at the surface (not shown).

A substantially cylindrical cuttings hopper 27 is secured on the upper end of stem 13 of auger 12. The diameter of hopper 27 is necessarily somewhat less than that of auger 12. A plurality of braces 28 extend from the rim of hopper 27 to a ring 29 rigidly attached on percussor 11. The wall of the hopper is formed with a slidabie gate 30 to facilitate removal of accumulated :3 cuttings. Auger 12 is hollow and provides an air passage to bit head 14 from air chamber 22 of percussor 11.

Cutting head 14 comprises a plate 31 having cutaway side portions as seen in FIGURE 4, and is secured as by bolts 32 and 33 to the lower end of the double-flighted auger 12. Three groups of drilling teeth numbered 34, 35 and 36, respectively, are removably secured to plate 31. These teeth are cylindrical in form and are positioned in bores 37 in the plate 31, and each tooth has a flange 38 which seats in a counterbore 39. Each tooth is held in its cylindrical seat by a snap ring 40 which locks against flange 39 of the tooth. Each tooth is formed with an end extension 41 which is eccentrically positioned and extends into a recess extension 42 of each bore 37. These tooth and bore extensions are differently positioned in the different groupings of the teeth, and it will be understood that the teeth are removable for sharpening or replacement, however, the tooth and bore extensions are so arranged that the teeth of one group will not fit in the bores of either of the other groups.

Pate 31 has a pair of beveled radial edges 43 in which tooth bores 37 are formed at an angle of substantially 30 from the plane of the plate, and the teeth 34 are secured in these bores.

A plurality of bores 37 are formed inwardly from the face of the plate 31 at a slight inclination, in which bores the teeth 35 are seated. A similar group of bores 37 are formed along the periphery of the plate at a slight angle in which teeth 36 are positioned. As can be seen from FIGURE 5, the teeth are all chisel-pointed but have differing point angles. Also, it will be seen that teeth 35 extend axially farther than the other teeth, and that teeth 36 extend beyond the periphery of plate 31. It will also be observed that each tooth 35 is disposed a dilterent radial distance from the center of rotation of the bit head 31 whereby a complete circular digging cut Will be made by these teeth.

Drill bit plate 31 is formed with a plurality of air ducts 44 leading from the auger stem bore and terminating in discharge ports 45 in the end face of the plate.

It is apparent at this point that various types of linear impact generators may be employed in the present drilling tool as the percussor 11. Preferably, however, the percussor is of the type illustrated in FIGURES 6-8 which show a standard reciprocating piston type, pneumatically operated impact generator or percussor, of the kind manufactured by the Mission Manufacturing Company of Houston, Texas, under the trade name Hammerdril. Since the illustrated percussor is conventional it will be described only in such detail as is necessary to enable a full and complete understanding of the invention.

The illustrated percussor 11 comprises an outer, generally cylindrical composite piston case 50, having an upper externally threaded end 52 which is threaded in the lower end of the air chamber 22. Extending coaxially through the piston case 50 is a control rod 54. Adjacent its upper end, the control rod has an external annular shoulder 56 which is located between and axially spaced from upper and lower internal annular shoulders 58 and 60 respectively, within the piston case 50. Surrounding the control rod between its external shoulder 56 and the internal shoulders 58 and 60 on the piston case are makeup rings 62 which axially position the control rod relative to the piston case. The upper end of the control rod extends above the upper case shoulder 58 into a chamber 64 in the upper end of the piston case. Chamber 64 communicates with the air chamber 22 through a passage 66 in the upper end of the piston case. Surrounding this passage is a valve seat 68. The upper end of the control rod 54 mounts a spring loaded check valve 70 which is engageable with the valve seat 68 to close the air passage when high pressure air is not being delivered to the drilling tool.

Extending coaxially through the control rod 54 is an air passage 72, the lower end of which is reduced and opens through the lower end of the rod. The control rod has upper and lower slots 74 and 76 milled in its outer surface. These slots do not communicate with the central air passage 72. Extending through the wall of the control rod, midway between the slots 74 and 76, are diametrically opposed ports 78 (only one shown) which communicate with the central passage 72. The control rod includes a pair (only one shown) of diametrically opposed exhaust passages 80 which parallel but do not communicate with the central air passage 72. The lower ends of the exhaust passages open through the lower end of the control rod. The exhaust passages also open radially to the exterior of the control rod through upper and lower exhaust ports 82 and 84, respectively. An 0- ring 86 is fitted on the lower end of the control rod.

Slidably received within the piston case 50 is an annular piston or hammer 88 which is slidably sealed to the interior surface of the piston case and the exterior surface of the control rod. The piston is internally relieved to form an inner annulus 90 between the piston and the control rod.

The impact piston 16 is annular in transverse cross section and is slidably received within the lower end of the piston case 50, above an internal annular shoulder 92 in the lower end of the piston case. Extending coaxially through the impact piston is an air passage 94 including a cylindrical portion 96 which receives the lower end of the control rod 54. The lower end of the impact piston extends below the lower end of the piston case and terminates in the mounting adaptor 15 which is rigidly secured to the stem 13 from the auger 12.

It will be recalled that the hopper 27 is drivably connected between the wall of the air chamber 22 and the auger 12 in such manner that the auger is driven in rotation from the kelly bar 18 through the hopper. This hopper also axially locates the impact piston 16 relative to the piston case 50 in a position wherein the lower seal ring 86 on the control rod 54 is received within the cylindrical portion 96 of the impact piston passage 94. The seal ring slidably seals the impact piston to the control rod, thereby preventing air flow between the piston and the control rod while accommodating relative movement of the piston with respect to the control rod. The inherent resiliency of the braces 28 which connect the hopper 27 to the wall of the air chamber 22 is sutficient to permit the axial vibratory motion of the impact piston 16, and thereby the auger 12, relative to the piston case 50 which occurs during operation of the percussor.

The lower end of the air passage 94 through the impact piston 16 communicates with the central passage through the hollow stem 13 of the auger 12. The upper end of the central air passage 72 through the control rod 54 communicates, just below the check balance 70, to the air chamber 64 in the upper end of the piston case 50 through a lateral branch passage 72a.

Assume now that the main piston 88 of the percussor occupies its lower limiting position in the piston case 50, wherein the lower end of the piston seats on the upper end of the impact piston 16, and that high pressure air is delivered to the percussor through the air hose 26. This air unseats the check valve 70 and flows through the chamber 64 into the central air passage 72 in the control rod 54. A portion of the air entering the latter passage flows through the lower, restricted end of the passage into the impact piston passage 94, and thence to the auger stem 13, through the air ducts 44 in the lower end of the auger. The remaining air entering the control rod passage 72 exits through the central air ports 78 in the control rod. It will be observed that when the piston 88 occupies its lower limiting position, the piston annulus 90 communicates the air ports 78 with the lower control rod slots 76. Accordingly, the air emerging from the control rod through its ports 78 flows downwardly through the slots 76 to the underside of the piston 88 and drives the piston upwardly in the piston case 50. During this upward travel of the piston in. the case, the piston annulus 9! rises above the. lower control rod slots 76, thereby. cutting off. air flow to the underside of the piston. The air trapped below the piston, however, continues to expand and thereby drive the piston upwardly. Shortly after the air flow to the under side of the upwardly traveling piston is cut off, the piston uncovers the lower exhaust port 84 in the control rod. The air below the piston is thereby vented to the exhaust passages St) through the passage 94' in the impact piston.

During the initial'upward travel of the piston 88from its lower limiting position, the upper exhaust port 82 is open, thereby venting the space above the piston to the impact piston, passage 94, through the exhaust passages 80. During this upward stroke of the pitton, andshcrtly after cut oif of air. flow to and venting-of the space below the piston, the upper exhaust port 82 is recovered by the piston and the piston annulus 90 rises above the upper control rod slots 74. High pressure air then flows from the central control rod passage 72, through the air ports 78, the annulus 90, the control rod slots 74, to the space above the piston 88. The piston is thereby driven downwardly to its lower limiting position. Upon the arrival of the piston in this position, it strikes the impact piston 16, thereby imparting a percussive blow to the auger 12. This operating cycle of the percussor 11 is repeated in rapid sequence so long as high pressure air is delivererd to the percussor. The auger, therefore, is subjected to a series of rapid impacts which tend to fracture the earth formation below the auger. It is apparent that the auger may be driven in rotation without operation of the percussor, the percussor may be operated without driving of the auger in rotation, or the percussor may be operated simultaneously with rotation of the auger. The exhaust air from the percussor is discharged through the ports 45 in the bit plate 31 and blows cuttings upwardly into the hopper 27.

The operation of the invention should be apparent from the foregoing description. Upon rotation of the drill by kelly bar 18 the teeth of bit head 14 will cut away the earth or other formation being drilled. The cuttings thusformed Will be carried upwardly along the the convolutions of auger 12. Upon the application of pressurized air to the percussor, the bit head will be actuated to loosen earth formations not eifectively done by auger action alone. The air stream emanating from the ports 45 in the bit head will. carry fine cuttings upwardy along the side wall of hopper 27 and be deposited therein through the open top thereof. Rocks and pebbles of a size too large to be thus lifted by the air stream will remain in the auger flights. The drill will need to be lifted out of the hole periodically to remove the accumulated cuttings from the hopper and the auger.

The intended mode of operation of this tool is to always impart a rotating action through the kelly drive. Then the application of air pressure will be used during selected periods of time. More specifically, when the formation which is a little too hard for the conventional auger cutting, then the percussion force is used in addition of the rotary action of the conventional auger drill.

Since ring 29 is rigidly attached to the drive spindle forming the upper part of percussor 11, rotation of the kelly bar causes cuttings hopper 27 to rotate. The auger 12 is coupled to the lower end of hopper 27 and is drivingly rotated thereby.

The invention has been described in considerable detail in order to comply with the patent laws by providing a full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the invention, or the scope of patent monopoly to be granted.

What is claimed is:

1. A percussion and rotary drill comprising;

a stationary bearing sleeve,

a drive spindle having a bearing mounting in said sleeve,

a hollow-shaft percussion and rotary'drill tool mounted to said drive spindle,

said tool including a percussor, acuttings hopper circumdisposed about said percussor, an auger extending below said percussor, a bit head secured to the forward-end of said auger, and means to supply air through said hollow shaft to said bit head.

2. A drill as set forth in claim 1 wherein said bit head has a plurality of groups of cutting teeth, the teeth of each of said groups being disposed at a different angle from those of the other groups.

3; A drill as set forth in claim 1 wherein said bit head has a plurality of groups of cutting teeth, each of said cutting, teeth having an axial. extent relative to said bit head measured in a direction parallel to the rotation axis of said auger, and said axial extent of the teeth of each of said groups being different than said axial extent of the teeth of the other groups.

4. A drill as set forth in claim 1 wherein said bit head has a plurality of tooth sockets and teeth, said teeth and sockets having interengaging orienting means for said teeth.

5. A drill as claimed in claim 4 wherein said teeth are individually removable from said bit head.

6. A percussion and rotary drill comprising,

a bearing sleeve having a stabilizing shoe,

a drive spindle having a bearing mounting in said sleeve,

an anger,

at cutting hopper intercoupling said auger and said drive spindle,

a pneumatic percussor concentrically disposed within said hopper, supported from said spindle and operatively coupled to said auger,

a bit head at the lower end of said auger having air discharge openings,

means to supply air pressure to said sleeve,

and air conduit means in said percussor and auger from said sleeve to said discharge openings.

7. A drill as claimed in claim 6 wherein said hopper is mounted above said auger and has openings in its upper part for receiving cuttings blown upwardly past said auger by the air stream from said bit head.

8. A drill as claimed in claim 7 wherein the diameter of said hopper is slightly less than the diameter of said auger.

9. A percussion and rotary drill comprising, in combination:

a drive spindle adapted for insertion into a drill hole;

a bearing sleeve adapted to receive said drive spindle, and having a stabilizing shoe adapted to engage the side of the hole;

air supply means attached to said bearing sleeve;

a substantially cylindrical cuttings hopper mounted below said spindle, and rigidly attached thereto to be rotatably driven thereby;

a flighted auger having a shaft, coupled to the lower end of said hopper;

a bit head at the lower end of said auger;

and a percussor disposed within said hopper and coupled between said drive spindle and said auger shaft, whereby said bit head may be driven either percussively or rotatively or both;

said cuttings hopper being of somewhat lesser diameter than said auger, and being open at its upper end for receiving cuttings;

said drive spindle, percussor and auger shaft having passageway means therein for conveying pressurized air to said bit head thereby to drive cuttings upward into said hopper.

10. A rotary drill adapted for concurrent application of percussive force, comprising in combination:

a stationary bearing sleeve;

7 8 a hollow drive spindle having a bearing mounting in auger, having a plurality of cutting bits thereon, and said sleeve; having a plurality of openings communicating with means for attaching a kelly bar to said drive spindle said hollow auger shaft, whereby compressed air supabove said sleeve; plied to said drive spindle flows out the face of said means associated with said sleeve for supplying com- 5 bit head and forces a portion of the cuttings upwar pressed air to the interior of said drive spindle; into said hopper. Y a hollow percussor attached to the lower end of said v drive spindle, and including a downwardly extending References Cited y the Examine! g lt l f r d 1 w h d UNITED STATES PATENTS a su san 121, y cy 1n rica cu mgs opper ispose about said percussor, having a lower end which 10 gg f zg'g closes around said impact piston, and an open upper 2,708,566 5/1955 Caldwell v 175 102 end with a plurality of radial ribs attached to said drive spindle;

a flighted auger having a hollow center shaft secured 15 to said impact piston, said auger being of some- What larger diameter than Said hopper; CHARLES E. OCONNELL, Przmary Exammer.

and a bit head mounted at the lower extremity of said BENJAMIN HERSH, Examiner.

2,915,288 12/1959 Crapez 175-102 2,989,295 6/1961 Prox 279-403 

1. A PERCUSSION AND ROTARY DRILL COMPRISING; A STATIONARY BEARING SLEEVE, A DRIVE SPINDLE HAVING A BEARING MOUNTING IN SAID SLEEVE, A HOLLOW-SHAFT PERCUSSION AND ROTARY DRILL TOOL MOUNTED TO SAID DRIVE SPINDLE, SAID TOOL INCLUDING A PERCUSSOR, A CUTTINGS HOPPER CIRCUMDISPOSED ABOUT SAID PERCUSSOR, AND AUGER EXTENDING BELOW SAID PERCUSSOR, A BIT HEAD SECURED TO THE FORWARD END OF SAID AUGER, AND MEANS TO SUPPLY AIR THROUGH SAID HOLLOW SHAFT TO SAID BIT HEAD. 